/Engine/Source/Runtime/Media/Public/IMediaSamples.h
virtual bool FetchCaption ( [TRange](API\Runtime\Core\Math\TRange)< [FMediaTimeStamp](API\Runtime\Media\FMediaTimeStamp) > TimeRange, [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [IMediaOverlaySample](API\Runtime\Media\IMediaOverlaySample), ESPMode::ThreadSafe > & OutSample )